Vitamin D deficiency in restless legs syndrome and chronic venous insufficiency: A comparative study

Abstract

Background & Objectives: Restless legs syndrome (RLS) and chronic venous insufficiency (CVI) are prevalent disorders with overlapping symptoms, complicating diagnosis. Vitamin D deficiency has been linked to neurological and vascular diseases, yet direct comparisons between RLS and CVI are scarce. This multicenter study evaluated serum vitamin D levels in patients with RLS, patients with CVI without RLS, and healthy controls to clarify disorder-specific associations.

Methods: We retrospectively analyzed 381 participants aged 18–65 years (127 RLS, 127 CVI, 127 controls) between October 2022 and March 2025. Demographic and biochemical parameters, including 25(OH)D, calcium, phosphorus, creatinine, and parathyroid hormone (PTH), were compared. Correlation analyses assessed relationships with disease duration and severity.

Results: Mean serum vitamin D was significantly lower in RLS (18.0 ± 9.4 ng/mL) and CVI (20.1 ± 6.6 ng/mL) compared with controls (24.8 ± 10.0 ng/mL, p<.001). Deficiency (<20 ng/mL) was found in 64.6% of RLS and 56.7% of CVI patients versus 27.6% of controls. In RLS, vitamin D levels negatively correlated with disease duration (r= –0.25, p=.032) and severity (r= –0.48, p<.001). In CVI, lower vitamin D correlated with longer disease duration (r= –0.28, p=.018) and higher clinical stage (r= –0.26, p<.001). PTH was significantly elevated in both patient groups.

Conclusions: Vitamin D deficiency is highly prevalent in RLS and CVI and correlates with disease burden, particularly in severe RLS. These findings indicate an association between reduced vitamin D levels and disease burden in both RLS and CVI, without implying a causal relationship. Routine screening of vitamin D status may be considered as part of clinical evaluation, although interventional implications require confirmation in prospective studies